There are well-known substrate units in which a conductive member (also referred to as a bus bar, for example) that is part of a circuit that allows a relatively large current to pass therethrough is fixed to a substrate on which a conductive pattern that is part of a circuit that allows a relatively small current to pass therethrough is formed (for example, see JP2003-164039A below). Such a substrate unit includes a heat dissipation member that is fixed to one side of the conductive member (the side opposite the substrate side).
In order to improve heat dissipation efficiency, it is preferable that the heat dissipation member is located on the upper side. However, in conventional substrate units such as the substrate unit disclosed in the JP2003-164039A above, if the heat dissipation member is located on the upper side, a portion that electrically connects other electrical devices to the unit (the portion with number 54 in JP2003-164039A above) is located on the lower side, and a problem such as degradation in workability occurs at the time of assembly.
A problem to be solved by the present invention is to provide a substrate unit that is able to improve heat dissipation efficiency while preventing workability from degrading at the time of assembly.